Hypotheses: 1) intraprostatic inflammation and focal atrophy contribute to lower urinary tract symptoms (LUTS) irrespective of transition zone hyperplasia or benign prostatic hyperplasia (BPH) diagnosis;and 2) finasteride reduces inflammation and atrophy extent, and thus LUTS. Chronic infiammatory infiltrates are common in BPH nodules, and inflammation extent predicts LUTS progression: these studies were done using tissue removed for indication, which might skew inflammation extent or bias the inflammation-LUTS correlation. We suspect that inflammation throughout the prostate, not only nodular, is associated with LUTS as it may a) reflect history of prostate infection/damage or propensity to mount an inflammatory response to insults, and b) influence LUTS via direct irritation by cytokines elaborated by immune cells with resultant tissue damage and regeneration. Further, whether morphological changes in focal atrophy, a probable regenerative lesion that is often inflamed, is etiologically linked with LUTS is unknown. To test our hypotheses, we propose multidisciplinary studies in 600 men who at entry in the Prostate Cancer Prevention Trial (PCPT) did not have clinical BPH and per protocol underwent biopsy at trial end irrespective of indication. We will sample age and race-matched men by LUTS severity at trial end and by 7-year change in LUTS from entry to end. In the placebo arm, we will evaluate whether a) inflammation or focal atrophy extent and b) immune cell profiles in prostate biopsies differs by LUTS severity or change over time. We will assess whether a) and b) differ by finasteride and placebo arms. Inflammation and atrophy will be quantified by image analysis of biopsy sections. Immune cell profiles will be evaluated by immunohistochemical staining for neutrophils, mast cells (c-KIT), TH17 cells (CD4+, IL23R), T regs (CD4+, FoxP3+), cytotoxic T cells (CD8+, exhausted PD-1+ and LAG-3+), macrophages (CD68+, activated MHC class II+), and dendritic cells (CD11c+, activated MHC class II+). Our team will conduct the first large study of men without clinical BPH to 1) characterize intraprostatic immune milieu and focal atrophy in relation to LUTS in men without indication for biopsy and 2) assess influence of finasteride on inflammation and atrophy, and thus LUTS.